Dispensers may be used to dispense any type of product, such as a chemical product, a cleaning product, a food or beverage product, and so forth. The product may be dispensed from via any suitable technique. For example, in one type of dispenser, a diluent is used to erode and/or dissolve a product, such as a detergent, in order to dispense a portion of the product from the container. The product being dispensed may be a solid product in the form of either a solid block of chemical, pellets or a cast product. Such a dispenser may include a spray nozzle for directing a uniform dissolving spray on to a surface of a solid block of cleaning composition. The nozzle directs a liquid at an exposed surface of the solid block to dissolve and/or erode a portion of the block and forming a product concentrate (also known as a “use solution”).
In certain applications it may be desirable to determine the amount of product dispensed and/or the amount of product remaining. One type of system that allows determination of the amount of product dispensed and/or the amount of product remaining is a mass-based dispensing system. Examples of mass-based dispensing systems are shown and described in co-pending and commonly assigned U.S. patent applications Ser. No. 10/437,257, entitled “Method and Apparatus for Mass Based Dispensing,” filed May 12, 2003 to Richard J. Mehus, et al; Ser. No. 10/436,454, entitled “Methods of Dispensing,” filed May 12, 2003, to Richard J. Mehus, et al; Ser. No. 10/843,219, entitled “Method and Apparatus for Mass Based Dispensing,” filed May 12, 2004 to Richard J. Mehus, et al; and Ser. No. 10/843,230, entitled “Method and Apparatus for Mass Based Dispensing,” filed May 11, 2004, to Richard J. Mehus, et al., all of which are incorporated herein by reference in their entirety.